In a conventional portable terminal device, from the aspect of usage of the device, portability was considered to be the most important, and so as a necessity, the display has been designed to be more compact. However, depending on the information to be displayed, a small screen may be very difficult for users having reduced vision or for elderly users to see. Therefore, in order for such users to be able to view the displayed information, the user typically has to use glasses or a magnifying glass. In order to improve this situation, technology for enlarging the displayed information on a portable terminal device has been disclosed, such as described below.
In the case of the portable terminal device disclosed in Patent Literature 1, when a cursor is placed on a menu or image that is being displayed, the location being focused on is enlarged, and when compared with the information before being focused on, the information is displayed in more detail. In the case of the portable terminal device disclosed in Patent Literature 2, a few characteristic coordinates of the displayed information, such as the contrast of the data, are taken, and based on these, the range to be enlarged is automatically extracted, enlarged and displayed in a partitioned display area on the same display screen. In the case of the portable terminal device disclosed in Patent Literature 3, a touch panel is used on the display screen, and the displayed information that is located inside the area to be enlarged that corresponds to the coordinates touched by the user is enlarged and displayed in another area on the same screen. When doing this, operability is improved by setting which hand is the user's dominant hand. Moreover, control is performed in order that overlapping of the area to be enlarged or the enlarged display area, which is caused by movement of the touched area, can be avoided. Furthermore, by assigning an order of display priority for the enlarged screen display area, the enlarged display area is located in an area where there is a smaller amount of information, and where displaying the enlarged display area will not be a problem.